Gas distributor with pre-chambers arranged in planes

Abstract

A gas distributor for a CVD or OVPD reactor comprises two or more gas volumes (1, 2) into each of which opens a feed pipe (3, 4) for a process gas, each gas volume (1, 2) being connected to a plurality of corresponding process gas outlets (6, 7) which open into the bottom (5) of the gas distributor. In order to increase the homogeneity of the gas composition, the two gas volumes (1, 2) comprise pre-chambers (10, 10′, 11) located in a first common plane (8) and a plurality of gas distribution chambers (12, 13) each associated with a gas volume are provided in a second plane (9′) adjacent to the bottom of the gas distributor. The pre-chambers (10, 10′, 11) and gas distribution chambers (12, 13) associated with each gas volume (1, 2) are connected with connection channels (14, 15).

1. A gas distributor in a CVD or OVPD reactor with two or more gas volumes ( 1 ,  2 ), into each of which a supply line ( 3 ,  4 ) for a process gas opens out, each gas volume ( 1 ,  2 ) being connected to a multiplicity of outlet openings ( 6 ,  7 ) for a respective one of the process gases, which open out in a bottom ( 5 ) of the gas distributor, the process gases respectively being first distributed in a radial direction in a first plane ( 8 ), remote from the bottom ( 5 ), and then distributed in a circumferential direction in a second plane ( 9 ′), adjacent to the bottom ( 5 ), and flowing through connecting channels ( 14 ,  15 ), which are located in a third plane ( 9 ) disposed between the first plane and the second plane, and a multiplicity of gas distributing chambers ( 12 ,  13 ) that are respectively associated with the gas volumes ( 1 ,  2 ) and are connected to the outlet openings ( 6 ,  7 ) being provided in the second plane ( 9 ′), the gas distributor characterized in that the gas volumes ( 1 ,  2 ) have pre-chambers ( 10 ,  10 ′,  11 ), at least one pre-chamber of one gas volume and at least one pre-chamber of another gas volume lying at a common elevation in the first plane ( 8 ), the pre-chambers ( 10 ,  10 ′,  11 ) of the two gas volumes ( 1 ,  2 ) forming continuations like prongs of a comb that extend in the radial direction and engage with one another in a manner of prongs of a comb, the comb-like continuations that lie next to one another in the circumferential direction being separated from one another by a wall ( 17 ). 
     
     
       2. The gas distributor according to  claim 1 , further characterized in that pre-chambers ( 10 ,  10 ′,  11 ) associated with one of the gas volumes ( 1 ,  2 ) are at different radial distances from a center of the gas distributor. 
     
     
       3. The gas distributor according to  claim 1 , further characterized in that different ones of the pre-chambers ( 10 ) of a first one of the gas volumes are disposed separately from one another in the circumferential direction. 
     
     
       4. The gas distributor according to  claim 1 , further characterized in that each pre-chamber ( 10 ,  10 ′,  11 ) is fed by more than one supply line ( 3 ,  4 ). 
     
     
       5. The gas distributor according to  claim 1 , further characterized in that a first one of the gas volumes is provided for feeding a gaseous, in particular metal-containing or semiconductor-containing, starting material and a second one of the gas volumes is provided for a chemically reactive gas, in particular an oxygen, nitrogen or hydrogen compound. 
     
     
       6. The gas distributor according to  claim 1 , further characterized in that the gas distributing chambers ( 12 ,  13 ) concentrically surround a center of the gas distributor. 
     
     
       7. The gas distributor according to  claim 1 , further characterized in that one or more of the gas distributing chambers ( 12 ,  13 ) are connected to a number of the pre-chambers ( 10 ,  10 ′,  11 ) by the connecting channels ( 14 ,  15 ). 
     
     
       8. The gas distributor according to  claim 1 , further characterized in that at least one of the pre-chambers is connected to a number of the gas distributing chambers by the connecting channels. 
     
     
       9. The gas distributor according to  claim 1 , further characterized in that the gas distributing chambers ( 12 ,  13 ) are disposed at different elevations within the second plane ( 9 ′). 
     
     
       10. The gas distributor according to  claim 1 , further characterized in that a temperature of the gas distributor is controlled. 
     
     
       11. The gas distributor according to  claim 1 , further characterized in that the gas distributor is produced from solid metal parts, which form a thermal mass for temperature homogenization. 
     
     
       12. The gas distributor according to  claim 1 , further characterized in that the gas distributor comprises a number of disks placed on one another, into which the pre-chambers ( 10 ,  10 ′,  11 ), the gas distributing chambers ( 12 ,  13 ), the connecting channels ( 14 ,  15 ) and the outlet openings ( 6 ,  7 ) are machined. 
     
     
       13. The gas distributor according to  claim 1 , further characterized in that portions of the at least one pre-chamber of one gas volume and portions of the at least one pre-chamber of another gas volume alternate with one another in a circumferential direction of the gas distributor. 
     
     
       14. The gas distributor according to  claim 1 , further characterized in that the gas distributing chambers of one gas volume and the gas distributing chambers of another gas volume alternate with one another in a radial direction of the gas distributor.